Controlling the thickness of a thin film layer takes a large part in determining quality in a semiconductor process and FPD process, and thus it is essential to directly monitor the thin film layer during the process. A ‘thin film layer’ is a base layer having a very thin thickness formed on a surface of a substrate, the thickness being generally between several nm and several μm. In order to apply such a thin film layer to certain uses, it is necessary to know the thickness, composition, illumination and other physical and optical characteristics of the thin film layer. Herein, there are various methods for measuring a thickness of a thin film layer to be used in a semiconductor process and other application processes, but the most general methods are those using an interferometer or a spectrophotometer.
Meanwhile, for semiconductor devices such as a LCD panel having color information such as R/G/B, recently a lot of interest is being paid to a technology for measuring color information such as R/G/B at the same time of measuring physical and optical characteristics of the thin film layer.
FIG. 1 is a right path view schematically illustrating a conventional three-dimensional shape measurement apparatus. According to FIG. 1, a conventional three-dimensional shape measurement apparatus includes a light source 10, light divider 30, lens unit 40, and light detector 50. The conventional three-dimensional shape measurement apparatus measures a shape of a certain object by observing the interference phenomenon that occurs as a light is divided into two or more light streams at the lens unit 40, generating a difference in proceeding paths, and then the divided lights are combined again.
However, such a conventional three-dimensional shape measurement apparatus cannot measure the exact color information of a certain object due to the interference effect of light, and thus it is general to identify a shape of the certain object based on the patterns formed differently per color on the measurement object.
That is, the conventional technology does not directly identify the measurement object differently per color information, and thus there occurs a problem that in a case where a pattern is not formed on the measurement object or where a pattern is formed identically per color, it is not possible to make a measurement differently per color information.